The present invention relates to dishwashing compositions comprising particular types of inproved alkylbenzene sulfonate surfactant mixtures adapted for use by controlling compositional parameters, especially a 2/3-phenyl index and a 2-methyl-2-phenyl index.
Historically, highly branched alkylbenzene sulfonate surfactants, such as those based on tetrapropylene, known as xe2x80x9cABSxe2x80x9d or xe2x80x9cTPBSxe2x80x9d, were used in detergents. However, these were found to be very poorly biodegradable. A long period followed of improving manufacturing processes for alkylbenzene sulfonates, making them as linear as practically possible, hence the acronym xe2x80x9cLASxe2x80x9d. The overwhelming part of a large art of linear alkylbenzene sulfonate surfactant manufacture is directed to this objective. All relevant large-scale commercial alkylbenzene sulfonate processes in use today are directed to linear alkylbenzene sulfonates. However, linear alkylbenzene sulfonates are not without limitations; for example, they would be more desirable if improved for hard water cleaning and/or cold water cleaning properties. They can often fail to produce good cleaning results, for example when. used in hard water areas.
As a result of the limitations of the alkylbenzene sulfonates, consumer cleaning formulations have often needed to include a higher level of cosurfactants, builders, and other additives than would have been needed given a superior alkylbenzene sulfonate.
The art of alkylbenzene sulfonate detergents is replete with references which teach both for and against almost every aspect of these compositions. Moreover, there are believed to be erroneous teachings and technical misconceptions about the mechanism of LAS operation under in-use conditions, particularly in the area of hardness tolerance. The volume of such references debases the art as a whole and makes it difficult to select the useful teachings from the useless without repeated experimentation. To further understand the state of the art, it should be appreciated that there has been not only a lack of clarity on which way to go to fix the unresolved problems of linear LAS, but also a range of misconceptions, not only in the understanding of biodegradation but also in basic mechanisms of operation of LAS in presence of hardness.
Also, while the currently commercial, essentially linear alkylbenzene sulfonate surfactants are relatively simple compositions to define and analyze, compositions containing both branched and linear alkylbenzene sulfonate surfactants are complex. In general such compositions can be highly varied, containing one or more different kinds of branching in any of a number of positions on the aliphatic chain. A very large number, e.g., hundreds, of distinct chemical species are possible in such mixtures. Accordingly there is an onerous burden of experimentation if it is desired to improve such compositions so that they can clean better in detergent compositions while at the same time remaining biodegradable. The formulator""s knowledge is key to guiding this effort.
Yet another currently unresolved problem in alkylbenzene sulfonate manufacture is to make more effective use of current LAB feedstocks. It would be highly desirable, both from a performance point of view and from an economic point of view, to better utilize certain desirable types of branched hydrocarbons.
Accordingly there is a substantial unmet need for further improvements in alkylbenzene sulfonate surfactant mixtures, especially with respect to those offering one or more of the advantages of superior cleaning, hardness tolerance, satisfactory biodegradability, and cost.
U.S. Pat. Nos. 5,659,099, 5,393,718, 5,256,392, 5,227,558, 5,139,759, 5,164,169, 5,116,794, 4,840,929, 5,744,673, 5,522,984, 5,811,623, 5,777,187, WO 9,729,064, WO 9,747573, WO 9,729,063, U.S. Pat. Nos. 5,026,933; 4,990,718; 4,301,316; 4,301,317; 4,855,527; 4,870,038; 2,477,382; EP 466,558, Jan. 15, 1992; EP 469,940, Feb. 5, 1992; FR 2,697,246, Apr. 29, 1994; SU 793,972, Jan. 7, 1981; U.S. Pat. Nos. 2,564,072; 3,196,174; 3,238,249; 3,355,484; 3,442,964; 3,492,364; 4,959,491; WO 88/07030, Sep. 25, 1990; U.S. Pat. Nos. 4,962,256, US 5,196,624; 5,196,625; EP 364,012 B, Feb. 15, 1990; U.S. Pat. Nos. 3,312,745; 3,341,614; 3,442,965; 3,674,885; 4,447,664; 4,533,651; 4,587,374; 4,996,386; 5,210,060; 5,510,306; WO 95117961, Ju. 6, 1995; WO 95/18084; U.S. Pat. Nos. 5,510,306; 5,087,788; 4,301,316; 4,301,317; 4,855,527; 4,870,038; 5,026,933; 5,625,105 and 4,973,788. See Vol 56 in xe2x80x9cSurfactant Sciencexe2x80x9d series, Marcel Dekker, New York, 1996, including in particular Chapter 2 entitled xe2x80x9cAlkylarylsulfonates: History, Manufacture, Analysis and Environmental Propertiesxe2x80x9d, pages 39-108, xe2x80x9cSurfactant Sciencexe2x80x9d series, Vol 73, Marcel Dekker, New York, 1998 and xe2x80x9cSurfactant Sciencexe2x80x9d series, Vol 40, Marcel Dekker, New York, 1992. See also copending U.S. patent applications Ser. No. 60/053,319 filed on Jul. 21st, 1997, Ser. No. 60/053,318, filed on Jul. 21st, 1997, Ser. No. 60/053,321, filed on Jul. 21st, 1997, Ser. No. 60/053,209, filed on Jul. 21st, 1997, Ser. No. 60/053,328, filed on Jul. 21st, 1997, Ser. No. 60/053,186, filed on Jul. 21st, 1997 and the art cited therein. Documents referenced herein are incorporated in their entirety.
It has now been determined that the use of certain alkylbenzene sulfonate surfactant mixtures, hereinafter xe2x80x9cmodified alkylbenzene sulfonate surfactant mixturesxe2x80x9d, as outlined in detail below, leads to improved cleaning of tough food stains, removal of grease/oil, improved benefits in dissolution, rinsing and low temperature product stability when compared to the use LAS in conventional detergent compositions.
The hand dishwashing compositions according to the first embodiment of the present invention comprises:
(i) from about 0.01% to about 95%, preferably from about 1% to about 50%, preferably from about 2% to about 30%, by weight of composition of a modified alkylbenzene sulfonate surfactant mixture comprising:
(a) from about 60% to about 95% by weight, preferably from about 65% to about 90%, more preferably from about 70% to about 85%, by weight of surfactant mixture, a mixture of branched alkylbenzene sulfonates having formula (I): 
wherein L is an acyclic aliphatic moiety consisting of carbon and hydrogen, said L having two methyl termini and said L having no substituents other than A, R1 and R2; and wherein said mixture of branched alkylbenzene sulfonates contains two or more, preferably at least three, optionally more, of said branched alkylbenzene sulfonates differing in molecular weight of the anion of said formula (I) and wherein said mixture of branched alkylbenzene sulfonates has
a sum of carbon atoms in R1, L and R2 of from 9 to 15, preferably from 10 to 14;
an average aliphatic carbon content, i.e., based on R1, L and R2 and excluding A, of from about 10.0 to about 14.0 carbon atoms, preferably from about 11.0 to about 13.0, more preferably from about 11.5 to about 12.5; M is a cation or cation mixture, preferably M is selected from H, Na, K, Ca, Mg and mixtures thereof, more preferably M is selected from H, Na, K and mixtures thereof, more preferably still, M is selected from H, Na, and mixtures thereof, M having a valence q, typically from 1 to 2, preferably 1; a and b are integers selected such that said branched alkylbenzene sulfonates are electroneutral (a is typically from 1 to 2, preferably 1, b is 1); R1 is C1-C3 alkyl, preferably C1-C2 alkyl, more preferably methyl; R2 is selected from H and C1-C3 alkyl (preferably H and C1-C2 alkyl, more preferably H and methyl, more preferably H and methyl provided that in at least about 0.5, more preferably 0.7, more preferably 0.9 to 1.0 mole fraction of said branched alkylbenzene sulfonates, R2 is H); A is a benzene moiety (typically A is the moietyxe2x80x94C6H4xe2x80x94, with the SO3 moiety of Formula (I) in para- position to the L moiety, though in some proportion, usually no more than about 5%, preferably from 0 to 5% by weight, the SO3 moiety is ortho- to L); and
(b) from about 5% to about 40%, preferably from about 10% to about 35%, more preferably from about 15% to about 30%, by weight of surfactant mixture, of a mixture of nonbranched alkylbenzene sulfonates having formula (II): 
wherein a, b, M, A and q are as defined hereinbefore and Y is an unsubstituted linear aliphatic moiety consisting of carbon and hydrogen having two methyl termini, and wherein said Y has a sum of carbon atoms of from 9 to 15, preferably from 10 to 14, and said Y has an average aliphatic carbon content of from about 10.0 to about 14.0, preferably from about 11.0 to about 13.0, more preferably 11.5 to 12.5 carbon atoms; and
xe2x80x83wherein said modified alkylbenzene sulfonate surfactant mixture is further characterized by a 2/3-phenyl index of from about 275 to about 10,000, preferably from about 350 to about 1200, more preferably from about 500 to about 700; and also preferably wherein said modified alkylbenzene sulfonate surfactant mixture has a 2-methyl-2-phenyl index of less than about 0.3, preferably less than about 0.2, more preferably less than about 0.1, more preferably still, from 0 to 0.05;
(ii) from about 0.00001% to about 99.9% by weight of a conventional hand dishwashing adjunct;
wherein said composition is further characterized by a 2/3-phenyl index of from about 275 to about 10,000.
The hand dishwashing compositions according to the second embodiment of the present invention comprises:
(i) a modified alkylbenzene sulfonate surfactant mixture, preferably from about 0.01% to about 95%, more preferably from about 1% to about 50%, even more preferably from about 2% to about 30%, by weight of composition, comprising the product of a process comprising the steps of:
(I) alkylating benzene with an alkylating mixture;
(II) sulfonating the product of (I); and
(III) optionally but very preferably, neutralizing the product of (II);
xe2x80x83wherein said alkylating mixture comprises:
(a) from about 1% to about 99.9%, by weight of alkylating mixture of branched C9-C20 (preferably C9-C15, more preferably C10-C14) monoolefins, said branched monoolefins having structures identical with those of the branched monoolefins formed by dehydrogenating branched paraffins of formula R1LR2 wherein L is an acyclic aliphatic moiety consisting of carbon and hydrogen and containing two terminal methyls; R1 is C1 to C3 alkyl; and R2 is selected from H and C1 to C3 alkyl; and
(b) from about 0.1% to about 85%, by weight of alkylating mixture of C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic olefins;
xe2x80x83wherein said alkylating mixture contains said branched C9-C20 (preferably C9-C15, more preferably C10-C14) monoolefins having at least two different carbon numbers in said C9-C20 (preferably C9-C15, more preferably C10-C14) range, and has a mean carbon content of from about 9.0 to about 15.0 carbon atoms (preferably from about 10.0 to about 14.0, more preferably from about 11.0 to about 13.0, more preferably still from about 11.5 to about 12.5); and wherein said components (a) and (b) are at a weight ratio of at least about 15:85 (preferably having branched component (a) in excess of linear component (b), for example 51% or more by weight of (a) and 49% or less of (b), more preferably 60% to 95% by weight of (a) and 5% to 40% of (b), more preferably still 65% to 90% by weight of (a) and 10% to 35% of (b), more preferably still 70% to 85% by weight of (a) and 15% to 30% of (b) wherein these percentages by weight exclude any other materials, for example diluent hydrocarbons, that may be present in the process;
(ii) from about 0.00001% to about 99.9% by weight of composition of a conventional hand dishwashing adjunct;
wherein said composition is further characterized by a 2/3-phenyl index of from about 275 to about 10,000.
The hand dishwashing compositions according to the third embodiment of the present invention comprises:
(i) A modified alkylbenzene sulfonate surfactant mixture, preferably from about 0.01% to about 95%, more preferably from about 1% to about 50%, even more preferably from about 2% to about 30%, by weight of composition, consisting essentially of the product of a process comprising the steps, in sequence, of:
(I) alkylating benzene with an alkylating mixture;
(II) sulfonating the product of (I); and
(III) neutralizing the product of (II);
xe2x80x83wherein said alkylating mixture comprises:
(a) from about 1% to about 99.9%, by weight of alkylating mixture of a branched alkylating agent selected from the group consisting of:
(A) C9-C20 (preferably C9-C15, more preferably C10-C14) internal monoolefins R1LR2 wherein L is an acyclic olefinic moiety consisting of carbon and hydrogen and containing two terminal methyls;
(B) C9-C20 (preferably C9-C15, more preferably C10-C14) alpha monoolefins R1AR2 wherein A is an acyclic alpha-olefinic moiety consisting of carbon and hydrogen and containing one terminal methyl and one terminal olefinic methylene;
(C) C9-C20 (preferably C9-C15, more preferably C10-C14) vinylidene monoolefins R1BR2 wherein B is an acyclic vinylidene olefin moiety consisting of carbon and hydrogen and containing two terminal methyls and one internal olefinic methylene;
(D) C9-C20 (preferably C9-C15, more preferably C10-C14) primary alcohols R1QR2 wherein Q is an acyclic aliphatic primary terminal alcohol moiety consisting of carbon, hydrogen and oxygen and containing one terminal methyl;
(E) C9-C20 (preferably C9-C15, more preferably C10-C14) primary alcohols R1ZR2 wherein Z is an acyclic aliphatic primary nonterminal alcohol moiety consisting of carbon, hydrogen and oxygen and containing two terminal methyls; and
(F) mixtures thereof;
xe2x80x83wherein in any of (A)-(F), said R1 is C1 to C3 alkyl and said R2 is selected from H and C1 to C3 alkyl; and
(b) from about 0. 1% to about 85%, by weight of alkylating mixture of C9-C20 (preferably C9-C15, more preferably C10-C14) linear alkylating agent selected from C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic olefins, C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic alcohols and mixtures thereof;
xe2x80x83wherein said alkylating mixture contains said branched alkylating agents having at least two different carbon numbers in said C9-C20 (preferably C9-C15, more preferably C10-C14) range, and has a mean carbon content of from about 9.0 to about 15.0 carbon atoms, preferably from about 10.0 to about 14.0, more preferably from about 11.0 to about 13.0, more preferably still from about 11.5 to about 12.5; and wherein said components (a) and (b) are at a weight ratio of at least about 15:85 (preferably having branched component (a) in excess of linear component (b), for example 51% or more by weight of (a) and 49% or less of (b), more preferably 60% to 95% by weight of (a) and 5% to 40% of (b), more preferably still 65% to 90% by weight of (a) and 10% to 35% of (b), more preferably still 70% to 85% by weight of (a) and 15% to 30% of (b) wherein these percentages by weight exclude any other materials, for example diluent hydrocarbons, that may be present in the process).;
(i) from about 0.00001% to about 99.9% by weight of composition of a conventional hand dishwashing adjunct;
wherein said composition is further characterized by a 2/3-phenyl index of from about 275 to about 10,000.
In accordance with the fourth embodiments of the present invention, there are encompassed herein a number of alternate embodiments, such as those in which there is blending of the novel modified alkylbenzene sulfonate surfactant mixture of the invention with one or more other alkylbenzene sulfonate surfactants. In practical terms, such blending is usually encompassed before sulfonation and detergent formulation, but the outcome is a hand dishwashing composition containing a blend of the novel modified alkylbenzene sulfonate surfactant with other, known, alkylbenzene sulfonates. Such alternate embodiments of the invention nonlimitingly include those termed herein as xe2x80x9cmedium 2/3-phenyl surfactant systemxe2x80x9d. Such surfactant system essentially contain useful amounts of the modified alkylbenzene sulfonate surfactant, along with other known alkylbenzene sulfonates subject to specific provisions of the 2/3-phenyl index of the overall composition. Such hand dishwashing compositions include:
(i) from about 0.1% to about 95% by weight of composition of a medium 2/3-phenyl surfactant system consisting essentially of:
(1) from 1% preferably at least about 5%, more preferably at least about 10%) to about 60% (preferably less than about 50%, more preferably less than about 40%), by weight of surfactant system of a first alkylbenzene sulfonate surfactant, wherein said first alkylbenzene sulfonate surfactant is a modified alkylbenzene sulfonate surfactant mixture, said surfactant mixture comprising:
(a) from about 60% to about 95% by weight of surfactant mixture, a mixture of branched alkylbenzene sulfonates having formula (I): 
wherein L is an acyclic aliphatic moiety consisting of carbon and hydrogen, said L having two methyl termini and said L having no substituents other than A, R1 and R2; and wherein said mixture of branched alkylbenzene sulfonates contains two or more of said branched alkylbenzene sulfonates differing in molecular weight of the anion of said formula (I) and wherein said mixture of branched alkylbenzene sulfonates has
a sum of carbon atoms in R1, L and R2 of from 9 to 15;
an average aliphatic carbon content of from about 10.0 to about 14.0 carbon atoms; M is a cation or cation mixture having a valence q; a and b are integers selected such that said branched alkylbenzene sulfonates are electroneutral; R1 is C1-C3 alkyl; R2 is selected from H and C1-C3 alkyl; A is a benzene moiety; and
(b) from about 5% to about 40% by weight of surfactant mixture, of a mixture of nonbranched alkylbenzene sulfonates having formula (II): 
wherein a, b, M, A and q are as defined hereinbefore and Y is an unsubstituted linear aliphatic moiety consisting of carbon and hydrogen having two methyl termini, and wherein said Y has a sum of carbon atoms of from 9 to 15, preferably from 10 to 14, and said Y has an average aliphatic carbon content of from about 10.0 to about 14.0; and
xe2x80x83wherein said modified alkylbenzene sulfonate surfactant mixture is further characterized by a 2/3-phenyl index of from about 275 to about 10,000; and
(2) from 40% (preferably at least about 50%, more preferably at least about 60%) to about 99% (preferably less than about 95%, more preferably less than about 90%), by weight of surfactant system of a second alkylbenzene sulfonate surfactant, wherein said second alkylbenzene sulfonate surfactant is an alkylbenzene sulfonate surfactant mixture other than said modified alkylbenzene sulfonate surfactant mixture (1) (typically said second alkylbenzene sulfonate surfactant is a conmmercial C10-C14 linear alkylbenzene sulfonate surfactant, e.g., DETAL(copyright) process LAS or HF process LAS though in general any commercial linear (LAS) or branched (ABS, TPBS) type can be used); and wherein said second alkylbenzene sulfonate surfactant has a 2/3-phenyl index of from about 75 to about 160 (preferably from about 170 to about 265, more preferably from about 180 to about 255).;
xe2x80x83provided that said medium 2/3-phenyl surfactant system has a 2/3-phenyl index of from about 160 to about 275;
(i) from about 0.00001% to about 99.9% by weight of composition of a conventional hand dishwashing adjunct.
The above mentioned embodiments and other aspects of the present invention are more fully described and exemplified in the detailed description hereinafter.
All percentages, ratios and proportions herein are by weight, unless otherwise specified. All temperatures are in degrees Celsius (xc2x0C.) unless otherwise specified. All documents cited are in relevant part, incorporated herein by reference.
The invention, on the other hand, is not intended to encompass any wholly conventional hand dishwashing detergent compositions, such as those based exclusively on linear alkylbenzene sulfonates made by any process, or exclusively on known unacceptably branched alkylbenzene sulfonates such as ABS or TPBS.
It is preferred that when the detergent compositions of the present invention comprise any alkylbenzene sulfonate surfactant other than said modified alkylbenzene sulfonate surfactant mixture (for example as a result of blending into the detergent composition one or more commercial, especially linear, typically linear C10-C14, alkylbenzene sulfonate surfactants), said composition is further characterized by an overall 2/3-phenyl index of at least about 200, preferably at least about 250, more preferably at least about 350, more preferably still, at least about 500, wherein said overall 2/3-phenyl index is determined by measuring 2/3-phenyl index, as defined herein, on a blend of said modified alkylbenzene sulfonate surfactant mixture and said any other alkylbenzene sulfonate to be added to said composition, said blend, for purposes of measurement, being prepared from aliquots of said modified alkylbenzene sulfonate surfactant mixture and said other alkylbenzene sulfonate not yet exposed to any other of the components of said composition; and further provided that when said composition comprises any alkylbenzene sulfonate surfactant other than said modified alkylbenzene sulfonate surfactant mixture (for example as a result of blending into the composition one or more commercial, especially linear, typically linear C10-C14, alkylbenzene sulfonate surfactants), said composition is further characterized by an overall 2-methyl-2-phenyl index of less than about 0.3, preferably from 0 to 0.2, more preferably no more than about 0.1, more preferably still, no more than about 0.05, wherein said overall 2-methyl-2-phenyl index is to be determined by measuring 2-methyl-2-phenyl index, as defined herein, on a blend of said modified alkylbenzene sulfonate surfactant mixture and any other alkylbenzene sulfonate to be added to said composition, said blend, for purposes of measurement, being prepared from aliquots of said modified alkylbenzene sulfonate surfactant mixture and said other alkylbenzene sulfonate not yet exposed to any other of the components of said composition. These provisions may appear somewhat unusual, however they are consistent with the spirit and scope of the present invention, which encompasses a number of economical but less preferred approaches in terms of overall cleaning performance, such as blending of the modified alkylbenzene sulfonate surfactants with conventional linear alkylbenzene sulfonate surfactants either during synthesis or during formulation into the detergent composition. Moreover, as is well known to practitioners of detergent analysis, a number of detergent adjuncts (paramagnetic materials and sometimes even water) are capable of interfering with methods for determining the parameters of alkylbenzene sulfonate surfactant mixtures as described hereinafter. Hence wherever possible, analysis should be conducted on dry materials before mixing them into the compositions.
Moreover, the invention encompasses the addition of useful hydrotrope precursors and/or hydrotropes, such as C1-C8 alkylbenzenes, more typically toluenes, cumenes, xylenes, naphthalenes, or the sulfonated derivatives of any such materials, minor amounts of any other materials, such as tribranched alkylbenzene sulfonate surfactants, dialkylbenzenes and their derivatives, dialkyl tetralins, wetting agents, processing aids, and the like. It will be understood that, with the exception of hydrotropes, it will not be usual practice in the present invention to include any such materials. Likewise it will be understood that such materials, if and when they interfere with analytical methods, will not be included in samples of compositions used for analytical purposes.
A preferred modified alkylbenzene sulfonate surfactant mixture according to first embodiment of the present invention has M selected from H, Na, K and mixtures thereof, said a=1, said b=1, said q=1, and said modified alkylbenzene sulfonate surfactant mixture has a 2-methyl-2-phenyl index of less than about 0.3, preferably less than about 0.2, more preferably from 0 to about 0.1.
Such a modified alkylbenzene sulfonate surfactant mixture according can be made as the product of a process using as catalyst a zeolite selected from mordenite, offretite and H-ZSM-12 in at least partially acidic form, preferably an acidic mordenite (in general certain forms of zeolite beta can be used as an alternative but are not preferred). Embodiments described in terms of their making, as well as suitable catalysts, are all further detailed hereinafter.
Another hand dishwashing composition according to the first embodiment of the invention wherein said modified alkylbenzene sulfonate surfactant mixture consists essentially of said mixture of (a) and (b), said 2-methyl-2-phenyl index of said modified alkylbenzene sulfonate surfactant mixture is less than about 0.1, said average aliphatic carbon content is from about 11.5 to about 12.5 carbon atoms; said R1 is methyl; said R2 is selected from H and methyl provided that in at least about 0.7 mole fraction of said branched alkylbenzene sulfonates R2 is H; and wherein said sum of carbon atoms in R1, L and R2 is from 10 to 14; and further wherein in said mixture of nonbranched alkylbenzene sulfonates, said Y has a sum of carbon atoms of from 10 to 14 carbon atoms, said average aliphatic carbon content of said nonbranched alkylbenzene sulfonates is from about 11.5 to about 12.5 carbon atoms, and said M is a monovalent cation or cation mixture selected from H, Na and mixtures thereof.
Definitions
Methyl termini
The terms xe2x80x9cmethyl terminixe2x80x9d and/or xe2x80x9cterminal methylxe2x80x9d mean the carbon atoms which are the terminal carbon atoms in alkyl moieties, that is L, and/or Y of formula (I) and formula (II) respectively are always bonded to three hydrogen atoms. That is, they will form a CH3xe2x80x94 group. To better explain this, the structure below shows the two terminal methyl groups in an alkylbenzene sulfonate. 
The term xe2x80x9cABxe2x80x9d herein when used without further qualification is an abbreviation for xe2x80x9calkylbenzenexe2x80x9d of the so-called xe2x80x9chardxe2x80x9d or nonbiodegradable type which on sulfonation forms xe2x80x9cABSxe2x80x9d. The term xe2x80x9cLABxe2x80x9d herein is an abbreviation for xe2x80x9clinear alkylbenzenexe2x80x9d of the current commercial, more biodegradable type, which on sulfonation forms linear alkylbenzene sulfonate, or xe2x80x9cLASxe2x80x9d. The term xe2x80x9cMLASxe2x80x9d herein is an abbreviation for the modified alkylbenzene sulfonate mixtures of the invention.
Impurities
The surfactant mixtures herein are preferably substantially free from impurities selected from tribranched impurities, dialkyl tetralin impurities and mixtures thereof. By xe2x80x9csubstantially freexe2x80x9d it is meant that the amounts of such impurities are insufficient to contribute positively or negatively to the cleaning effectiveness of the composition. Typically there is less than about 5%, preferably less than about 1%, more preferably about 0.1% or less of the impurity, that is typically no one of the impurities is practically detectable.
Illustrative Structures
The better to illustrate the possible complexity of modified alkylbenzene sulfonate surfactant mixtures of the invention and the resulting detergent compositions, structures (a) to (v) below are illustrative of some of the many preferred compounds of formula (I). These are only a few of hundreds of possible preferred structures that make up the bulk of the composition, and should not be taken as limiting of the invention. 
Structures (w) and (x) nonlimitingly illustrate less preferred compounds of Formula (I) which can be present, at lower levels than the above-illustrated preferred types of stuctures, in the modified alkylbenzene sulfonate surfactant mixtures of the invention and the resulting detergent compositions. 
Structures (y), (z), and (aa) nonlimitingly illustrate compounds broadly within Formula (I) that are not preferred but which can be present in the modified alkylbenzene sulfonate surfactant mixtures of the invention and the resulting detergent compositions. 
Structure (bb) is illustrative of a tri-branched structure not within Formula (I), but that can be present as an impurity.
Preferably the modified alkylbenzene sulfonate surfactant mixtures herein are the product of sulfonating a modified alkylbenzene, (other than well known tetrapropylene or AB types) wherein the modified alkylbenzene is produced by alkylating benzene with a branched olefin, other than tetrapropylene, and more particularly the lightly branched types described in more detail hereinafter, over an acidic mordenite-type catalyst or other suitable catalyst as defined elsewhere herein.
In certain cases, compositions herein can also be prepared by blending. Thus, the invention includes a hand dishwashing composition using a modified alkylbenzene sulfonate surfactant mixture according to the first embodiment wherein said modified alkylbenzene sulfonate surfactant mixture is prepared by a process comprising a step selected from: (i) blending a mixture of branched and linear alkylbenzene sulfonate surfactants having a 2/3-phenyl index of 500 to 700 with an alkylbenzene sulfonate surfactant mixture having a 2/3-phenyl index of 75 to 160 and (ii) blending a mixture of branched and linear alkylbenzenes having a 2/3-phenyl index of 500 to 700 with an alkylbenzene mixture having a 2/3-phenyl index of 75 to 160 and sulfonating said blend. However when a modified alkylbenzene sulfonate surfactant mixture is prepared in this fashion, the resulting surfactant mixture will have a 2/3-phenyl index of from about 275 to about 10,000.
In outline, modified alkylbenzene sulfonate surfactant mixtures herein can be made by the steps of:
(I) alkylating benzene with an alkylating mixture;
(II) sulfonating the product of (I); and (optionally but very preferably)
(III) neutralizing the product of (II).
Provided that suitable alkylation catalysts and process conditions as taught herein are used, the product of step (I) is a modified alkylbenzene mixture in accordance with the invention. Provided that sulfonation is conducted under conditions generally known and reapplicable from LAS manufacture, see for example the literature references cited herein, the product of step (II) is a modified alkylbenzene sulfonic acid mixture in accordance with the invention. Provided that neutralization step (III) is conducted as generally taught herein, the product of step (III) is a modified alkylbenzene sulfonate surfactant mixture in accordance with the invention. Since neutralization can be incomplete, mixtures of the acid and neutralized forms of the present modified alkylbenzene sulfonate systems in all proportions, e.g., from about 1000:1 to 1:1000 by weight, are also part of the present invention. Overall, the greatest criticalities are in step (I).
Preferred modified alkylbenzene sulfonate surfactant mixtures herein comprise the product of a process comprising the steps of: (I) alkylating benzene with an alkylating mixture; (II) sulfonating the product of (I); and (optionally but very preferably) (III) neutralizing the product of (II); wherein said alkylating mixture comprises: (a) from about 1% to about 99.9%, by weight of branched C9-C20 (preferably C9-C15, more preferably C10-C14) monoolefins, said branched monoolefins having structures identical with those of the branched monoolefins formed by dehydrogenating branched paraffins of formula R1LR2 wherein L is an acyclic aliphatic moiety consisting of carbon and hydrogen and containing two terminal methyls; R1 is C1 to C3 alkyl; and R2 is selected from H and C1 to C3 alkyl; and (b) from about 0.1% to about 85%, by weight of C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic olefins; wherein said alkylating mixture contains said branched C9-C20 monoolefins having at least two different carbon numbers in said C9-C20 range, and has a mean carbon content of from about 9.0 to about 15.0 carbon atoms (preferably from about 10.0 to about 14.0, more preferably from about 11.0 to about 13.0, more preferably still from about 11.5 to about 12.5); and wherein said components (a) and (b) are at a weight ratio of at least about 15:85 (preferably having branched component (a) in excess of linear component (b), for example 51% or more by weight of (a) and 49% or less of (b), more preferably 60% to 95% by weight of (a) and 5% to 40% of (b), more preferably still 65% to 90% by weight of (a) and 10% to 35% of (b), more preferably still 70% to 85% by weight of (a) and 15% to 30% of (b) wherein these percentages by weight exclude any other materials, for example diluent hydrocarbons, that may be present in the process).
Also encompassed herein are modified alkylbenzene sulfonate surfactant mixtures consisting essentially of the product of a process comprising the steps, in sequence, of: (I) alkylating benzene with an alkylating mixture; (II) sulfonating the product of (I); and (III) neutralizing the product of (I); wherein said alkylating mixture comprises: (a) from about 1% to about 99.9%, by weight of a branched alkylating agent selected from: (A) C9-C20 (preferably C9-C15, more preferably C10-C14) internal monoolefins R1LR2 wherein L is an acyclic olefinic moiety consisting of carbon and hydrogen and containing two terminal methyls; (B) C9-C20 (preferably C9-C15, more preferably C10-C14) alpha monoolefins R1AR2 wherein A is an acyclic alpha-olefinic moiety consisting of carbon and hydrogen and containing one terminal methyl and one terminal olefinic methylene; (C) C9-C20 (preferably C9-C15, more preferably C10-C14) vinylidene monoolefins R1BR2 wherein B is an acyclic vinylidene olefin moiety consisting of carbon and hydrogen and containing two terminal methyls and one internal olefinic methylene; (D) C9-C20 (preferably C9-C15, more preferably C10-C14) primary alcohols R1QR2 wherein Q is an acyclic aliphatic primary terminal alcohol moiety consisting of carbon, hydrogen and oxygen and containing one terminal methyl; (E) C9-C20 (preferably C9-C15, more preferably C10-C14) primary alcohols R1ZR2 wherein Z is an acyclic aliphatic primary nonterminal alcohol moiety consisting of carbon, hydrogen and oxygen and containing two terminal methyls; and (F) mixtures thereof; wherein in any of (A)-(F), said R1 is C1 to C3 alkyl and said R2 is selected from H and C1 to C3 alkyl; and (b) from about 0.1% to about 85%, by weight of C9-C20 (preferably C9-C15, more preferably C10-C14) linear alkylating agent selected from C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic olefins, C9-C20 (preferably C9-C15, more preferably C10-C14) linear aliphatic alcohols and mixtures thereof; wherein said alkylating mixture contains said branched alkylating agents having at least two different carbon numbers in said C9-C20 (preferably C9-C15, more preferably C10-C14) range, and has a mean carbon content of from about 9.0 to about 15.0 carbon atoms (preferably from about 10.0 to about 14.0, more preferably from about 11.0 to about 13.0, more preferably still from about 11.5 to about 12.5); and wherein said components (a) and (b) are at a weight ratio of at least about 15:85 (preferably having branched component (a) in excess of linear component (b), for example 51% or more by weight of (a) and 49% or less of (b), more preferably 60% to 95% by weight of (a) and 5% to 40% of (b), more preferably still 65% to 90% by weight of (a) and 10% to 35% of (b), more preferably still 70% to 85% by weight of (a) and 15% to 30% of (b) wherein these percentages by weight exclude any other materials, for example diluent hydrocarbons, that may be present in the process).
In more highly preferred embodiments, the invention encompasses a modified alkylbenzene sulfonate surfactant mixture prepared in accordance with the above-outlined steps wherein said alkylating mixture consists essentially of: (a) from about 0.5% to about 47.5%, by weight of said branched alkylating agent selected from: (G) C9-C14 internal monoolefins R1LR2 wherein L is an acyclic olefinic moiety consisting of carbon and hydrogen and containing two terminal methyls; (H) C9-C14 alpha monoolefins R1AR2 wherein A is an acyclic alpha-olefinic moiety consisting of carbon and hydrogen and containing one terminal methyl and one terminal olefinic methylene; and (J) mixtures thereof; wherein in any of (G)-(H), said R1 is methyl, and said R2 is H or methyl provided that in at least about 0.7 mole fraction of the total of said monoolefins, R2 is H; and (b) from about 0.1% to about 25%, by weight Of C9-C14 linear aliphatic olefins; and (c) from about 50% to about 98.9%, by weight of carrier materials selected from paraffins and inert nonparaffinic solvents; wherein said alkylating mixture contains said branched alkylating agents having at least two different carbon numbers in said C9-C14 range, and has a mean carbon content of from about 11.5 to about 12.5 carbon atoms; and wherein said components (a) and (b) are at a weight ratio of from about 51:49 to about 90:10.
Other modified alkylbenzene sulfonate surfactant mixtures herein are made by the above-outlined processes wherein in step (I), said alkylation is performed in the presence of an alkylation catalyst, said alkylation catalyst is an intermediate acidity solid porous alkylation catalyst, and step (II) comprises removal of components other than monoalkylbenzene prior to contacting the product of step (I) with sulfonating agent.
Also encompassed is the modified alkylbenzene sulfonate surfactant mixture according to the above-defined processes wherein said alkylation catalyst is other than a member selected from the group consisting of HF, AlCl3, sulfuric acid and mixtures thereof. Such is the case when the alkylation catalyst is selected from the group consisting of non-fluoridated acidic mordenite-type catalyst, fluoridated acidic mordenite-type catalyst and mixtures thereof. Catalysts are described in more detail hereinafter.
The processes are tolerant of variation, for example conventional steps can be added before, in parallel with, or after the outlined steps (I), (II) and (III). This is especially the case for accomodating the use of hydrotropes or their precursors. Thus the invention encompasses a modified alkylbenzene sulfonate surfactant mixture according to the above-outlined processes wherein a hydrotrope, hydrotrope precursor, or mixtures thereof is added after step (I); or the hydrotrope, hydrotrope precursor or mixtures thereof is added during or after step (II) and prior to step (III); or a hydrotrope can be added during or after step (III).
Sulfonation and Workup or Neutralization (Steps II/III)
In general, sulfonation of the modified alkylbenzenes in the instant process can be accomplished using any of the well-known sulfonation systems, including those described in xe2x80x9cDetergent Manufacture Including Zeolite Builders and other New Materialsxe2x80x9d, Ed. Sittig., Noyes Data Corp., 1979, as well as in Vol. 56 in xe2x80x9cSurfactant Sciencexe2x80x9d series, Marcel Dekker, New York, 1996, including in particular Chapter 2 entitled xe2x80x9cAlkylarylsulfonates: History, Manufacture, Analysis and Environmental Propertiesxe2x80x9d, pages 39-108 which includes 297 literature references. This work provides access to a great deal of literature describing various processes and process steps, not only sulfonation but also dehydrogenation, alkylation, alkylbenzene distillation and the like. Common sulfonation systems useful herein include sulfuric acid, chlorosulfonic acid, oleum, sulfur trioxide and the like. Sulfur trioxide/air is especially preferred. Details of sulfonation using a suitable air/sulfur trioxide mixture are provided in U.S. Pat. No. 3,427,342, Chemithon. Sulfonation processes are further extensively described in xe2x80x9cSulfonation Technology in the Detergent Industryxe2x80x9d, W. H. de Groot, Kluwer Academic Publishers, Boston, 1991.
Any convenient workup steps may be used in the present process. Common practice is to neutralize after sulfonation with any suitable alkali. Thus the neutralization step can be conducted using alkali selected from sodium, potassium, ammonium, magnesium and substituted ammonium alkalis and mixtures thereof. Potassium can assist solubility, magnesium can promote soft water performance and substituted ammonium can be helpful for formulating specialty variations of the instant surfactants. The invention encompasses any of these derivative forms of the modified alkylbenzenesulfonate surfactants as produced by the present process and their use in consumer product compositions.
Alternately the acid form of the present surfactants can be added directly to acidic cleaning products, or can be mixed with cleaning ingredients and then neutralized.
The hydrotropes or hydrotrope precursors useful herein can in general be selected from any suitable hydrotrope or hydrotrope precursor, including lower alkyl (C1-C8) aromatics and their sulfonic acids and sulfonate salts, but are more typically based on a sulfonic acid or sodium sulfonate salt of toluene, cumene, xylene, napthalene or mixtures thereof. The hydrotrope precursors are selected from any suitable hydrotrope precursor, typically toluene, cumene, xylene, napthalene or mixtures thereof. A hydrotrope precursor is a compound that during step (ImI), namely the sulfonation step, is converted into a hydrotrope.
In terms of process conditions for alkylation, the invention encompasses a modified alkylbenzene sulfonate surfactant mixture wherein in step (I) said alkylation is performed at a temperature of from about 125xc2x0 C. to about 230xc2x0 C. (preferably from about 175xc2x0 C. to about 215xc2x0 C.) and at a pressure of from about 50 psig to about 1000 psig (preferably from about 100 psig to about 250 psig). Preferably in step (I) said alkylation is performed at a temperature of from about 175xc2x0 C. to about 215xc2x0 C., at a pressure of from about 100 psig to about 250 psig. and a time of from about 0.01 hour to about 18 hours (preferably, as rapidly as possible, more typically from about 0.1 hour to about 5 hours). If desired such alkylation may be conducted in one or more stages. Different stages of the process can be conducted in different manufacturing facilities. Typically in practice, LAB manufacturers will conduct step (I), with detergent manufacturers conducting step (III). Step (II) is typically conducted by either, or can even be conducted by third party manufacturers.
In general it is found preferable in step (I) to couple together the use of relatively low temperatures (e.g., 175xc2x0 C. to about 215xc2x0 C.) with reaction times of medium duration (1 hour to about 8 hours) in the above-indicated ranges.
It is possible even to xe2x80x9ctargetxe2x80x9d for desirably low 2-methyl-2-phenyl index in the present inventive compositions by selecting a relatively low reaction temperature, e.g., about 190xc2x0 C., and to monitor the progress of the reaction by any convenient means (e.g., sampling and NMR analysis) to assure adequate completion while minimizing 2-methyl-2-phenyl index.
Moreover, it is contemplated that the alkylation xe2x80x9cstepxe2x80x9d (I) herein can be xe2x80x9cstagedxe2x80x9d so that two or more reactors operating under different conditions in the defined ranges may be useful. By operating a plurality of such reactors, it is possible to allow for material with less preferred 2-methyl-2-phenyl index to be initially formed and, surprisingly, to convert such material into material with a more preferred 2-methyl-2-phenyl index.
In terms of sulfonating agent selection, the invention encompasses a modified alkylbenzene sulfonate surfactant mixture wherein step (II) is performed using a sulfonating agent selected from the group consisting of sulfur trioxide, sulfur trioxide/air mixtures, and sulfuric acid (including oleum). Chlorosulfonic acid or other known sulfonating agents, while less commercially relevant, are also useful and are included for use in the invention.
Although in general, neutralization step (III) can be carried out with any suitable alkali, the invention includes a modified alkylbenzene sulfonate surfactant mixture wherein said step (III) is performed using a basic salt, said basic salt having a cation selected from the group consisting of alkali metal, alkaline earth metal, ammonium, substituted ammonium, and mixtures thereof and an anion selected from hydroxide, oxide, carbonate, silicate, phosphate, and mixtures thereof. Preferred basic salt is selected from the group consisting of sodium hydroxide, sodium silicate, potassium hydroxide, potassium silicate, magnesium hydroxide, ammonium hydroxide, and mixtures thereof.
Alkylation Catalyst
To secure the modified alkylbenzene sulfonate surfactant mixtures of the invention, the present invention uses a particularly defined alkylation catalyst. Said alkylation catalyst is an intermediate acidity solid porous alkylation catalyst defined in detail hereinafter. Particularly preferred alkylation catalysts comprise at least partially dealuminized acidic fluoridated mordenites, at least partially dealuminized acidic nonfluoridated mordenites, and mixtures thereof.
Numerous alkylation catalysts are unsuitable for making the present modified alkylbenzene mixtures and modified alkylbenzene sulfonate surfactant mixtures. Unsuitable alkylation catalysts include any of: sulfuric acid, aluminum chloride, and HF. Also unsuitable are non-acidic calcium mordenite, and many others. Other catalysts, such as the DETAL(copyright) process catalysts of UOP are also unsuitable, at least in their current commercial executions. Indeed no alkylation catalyst currently used for alkylation in the commercial production of detergent C10-C14 linear alkylbenzene sulfonates for use in laundry products are suitable.
In contrast, suitable alkylation catalysts herein are selected from shape-selective moderately acidic alkylation catalysts, preferably zeolitic. The zeolite catalyst used for the alkylation step (I) is preferably selected from the group consisting of mordenite, HZSM-12, and offretite, any of these being in at least partially acidic form. Mixtures can be used and the catalysts can be combined with binders etc. as described hereinafter. More preferably, the zeolite is substantially in acid form and is contained in a catalyst pellet comprising a conventional binder and further wherein said catalyst pellet comprises at least about 1%, more preferably at least 5%, more typically from 50% to about 90%, of said zeolite.
More generally, a suitable alkylation catalyst is typically at least partially crystalline, more preferably substantially crystalline not including binders or other materials used to form catalyst pellets, aggregates or composites. Moreover the catalyst is typically at least partially acidic. Fully exchanged Ca-form mordenite, for example, is unsuitable whereas H-formn mordenite is suitable.
The pores characterizing the zeolites useful in the present alkylation process may be substantially circular, uniform pores of about 6.2 Angstrom, or preferably may be somewhat elliptical, such as in mordenite. It should be understood that, in any case, the zeolites used as catalysts in the alkylation step of the present process have a major pore dimension intermediate between that of the large pore zeolites, such as the X and Y zeolites, and the relatively small pore size zeolites ZSM-5 and ZSM-11, and preferably between about 6 Angstrom and about 7 Angstrom. Indeed ZSM-5 has been tried and found inoperable in the present invention. The pore size dimensions and crystal structures of certain zeolites are specified in ATLAS OF ZEOLITE STRUCTURE TYPES by W. M. Meier and D. H. Olson, published by the Structure Commission of the International Zeolite Association (1978 and more recent editions) and distributed by Polycrystal Book Service, Pittsburgh, Pa.
The zeolites useful in the alkylation step of the instant process generally have at least 10 percent of the cationic sites thereof occupied by ions other than alkali or alkaline-earth metals. Typical but non-limiting replacing ions include ammonium, hydrogen, rare earth, zinc, copper and aluminum. Of this group, particular preference is accorded ammonium, hydrogen, rare earth or combinations thereof. In a preferred embodiment, the zeolites are converted to the predominantly hydrogen form, generally by replacement of the alkali metal or other ion originally present with hydrogen ion precursors, e.g., ammonium ions, which upon calcination yield the hydrogen form. This exchange is conveniently carried out by contact of the zeolite with an ammonium salt solution, e.g., ammonium chloride, utilizing well known ion exchange techniques. In certain preferred embodiments, the extent of replacement is such as to produce a zeolite material in which at least 50 percent of the cationic sites are occupied by hydrogen ions.
The zeolites may be subjected to various chemical treatments, including alumina extraction (dealumination) and combination with one or more metal components, particularly the metals of Groups IIB, III, IV, VI, VII and VIII. It is also contemplated that the zeolites may, in some instances, desirably be subjected to thermal treatment, including steaming or calcination in air, hydrogen or an inert gas, e.g. nitrogen or helium.
A suitable modifying treatment entails steaming of the zeolite by contact with an atmosphere containing from about 5 to about 100% steam at a temperature of from about 250xc2x0 C. to 1000xc2x0 C. Steaming may last for a period of between about 0.25 and about 100 hours and may be conducted at pressures ranging from sub-atmospheric to several hundred atmospheres.
In practicing the desired alkylation step of the instant process, it may be useful to incorporate the above-described intermediate pore size crystalline zeolites in another material, e.g., a binder or matrix resistant to the temperature and other conditions employed in the process. Such matrix materials include synthetic or naturally occurring substances as well as inorganic materials such as clay, silica, and/or metal oxides. Matrix materials can be in the form of gels including mixtures of silica and metal oxides. The latter may be either naturally occurring or in the form of gels or gelatinous precipitates. Naturally occurring clays which can be composited with the zeolite include those of the montmorillonite and kaolin families, which families include the sub-bentonites and the kaolins commonly known as Dixie, McNamee-Georgia and Florida clays or others in which the main mineral constituent is halloysite, kaolinite, dickite, nacrite or anauxite. Such clays can be used in the raw state as originally mined or initially subjected to calcination, acid treatment or chemical modification.
In addition to the foregoing materials, the intermediate pore size zeolites employed herein may be compounded with a porous matrix material, such as alumina, silica-alumina, silica-magnesia, silica-zirconia, silica-thoria, silica-beryllia, and silica-titania, as well as ternary combinations, such as silica-alumina-thoria, silica-alumina-zirconia, silica-alumina-magnesia and silica-magnesia-zirconia. The matrix may be in the form of a cogel. The relative proportions of finely divided zeolite and inorganic oxide gel matrix may vary widely, with the zeolite content ranging from between about 1 to about 99% by weight and more usually in the range of about 5 to about 80% by weight of the composite.
A group of zeolites which includes some useful for the alkylation step herein have a silica:alumina ratio of at least 2:1, preferably at least 10:1 more preferably at least 20:1. The silica:alumina ratios referred to in this specification are the structural or framework ratios, that is, the ratio for the SiO4 to the AlO4 tetrahedra. In practice, silica:alumina ratios as determined by various physical and chemical methods are acceptable for use herein. It should be understood that such methods may acceptably give some variation. For example, a gross chemical analysis may include aluminum which is present in the form of cations associated with the acidic sites on the zeolite, thereby giving a somewhat low experimentally determined silica:alumina ratio. Similarly, if the ratio is determined by thermnogravimetric analysis (TGA) of ammonia desorption, a somewhat low ammonia titration may be obtained if cationic aluminum prevents exchange of the ammonium ions onto the acidic sites. These disparities are well known in the art. They can be troublesome when certain treatments, such as the dealuminization methods described below which result in the presence of ionic aluminum free of the zeolite structure, are employed. Due care should therefore be taken to ensure that the framework silica:alumina ratio is correctly determined to the extent acceptable to a practitioner of the art.
When the zeolites have been prepared in the presence of organic cations they are typically catalytically inactive, commonly because the intracrystalline free space is occupied by organic cations from the forming solution. They may be activated by heating in an inert atmosphere at 540xc2x0 C. for one hour, for example, followed by base exchange with ammonium salts followed by calcination at 540xc2x0 C. in air. The presence of organic cations in the forming solution may not be absolutely essential to the formation of the zeolite; but it does appear to favor the formation of this special type of zeolite. Some natural zeolites may sometimes be converted to zeolites of the desired type by various activation procedures and other treatments such as base exchange, steaming, alumina extraction and calcination. The zeolites preferably have a crystal framework density, in the dry hydrogen form, not substantially below about 1.6 g/cm3. The dry density for known structures may be calculated from the number of silicon plus aluminum atoms per 1000 cubic Angstroms, as given, e.g., on page 19 of the article on Zeolite Structure by W. M. Meier included in xe2x80x9cProceedings of the Conference on Molecular Sieves, London, April 1967xe2x80x9d, published by the Society of Chemical Industry, London, 1968. Reference is made to this paper for a discussion of the crystal framework density. A further discussion of crystal framework density, together with values for some typical zeolites, is given in U.S. Pat. No. 4,016,218, to which reference is made. When synthesized in the alkali metal form, the zeolite is conveniently converted to the hydrogen (acidic) form, generally via intermediate formation of the ammonium form by ammonium ion exchange and calcination of the ammonium form to yield the hydrogen form. It has been found that although the hydrogen form of the zeolite catalyzes the reaction successfully, the zeolite may also be partly in the alkali metal form and/or the form of other metal salts.
EP 466,558 describes an acidic mordenite type alkylation catalyst also of possible use herein having overall Si/Al atomic ratio of 15-85 (15-60), Na weight content is less than 1000 ppm (preferably less than 250 ppm), and there is a low or zero content of extra-network Al species; the elementary mesh volume as defined in EP 466,558 is below 2,760 nmn.
U.S. Pat. No. 5,057,472 is likewise useful for preparing alkylation catalysts herein and relates to concurrent dealumination and ion-exchange of an acid-stable Na ion-containing zeolite, preferably mordenite, effected by contact of the zeolite with a 0.5-3 (preferably 1-2.5) M HNO3 solution containing sufficient NH4NO3 to fully exchange the Na+ ions for NH4+ and H+ ions. The resulting zeolites can have a SiO2:Al203 ratio of 15:1 to 26:1, preferably 17:1 to 23:1, and are preferably calcined to at least partially convert the NH4+/H+ form to the H+ form. Optionally, though not necessarily particularly desirable in the present invention, the catalyst can contain a Group VIII metal (and optionally also an inorganic oxide) together with the calcined zeolite of ""472.
Another acidic mordenite catalyst useful for the alkylation step herein is disclosed in U.S. Pat. No. 4,861,935 which relates to a hydrogen form of mordenite incorporated with alumina, the composition having a surface area of at least 580 m2/g. Other acidic mordenite catalysts useful for the alkylation step herein include those described in U.S. Pat. Nos. 5,243,116 and 5,198,595. Yet another alkylation catalyst useful herein is described in U.S. Pat. No. 5,175,135 which is an acid mordenite zeolite having a silica/alumina molar ratio of at least 50:1, a Symmetry Index of at least 1.0 as determined by X-ray diffraction analysis, and a porosity such that the total pore volume is in the range from about 0.18 cc/g to about 0.45 cc/g and the ratio of the combined meso- and macropore-volume to the total pore volume is from about 0.25 to about 0.75.
Particularly preferred alkylation catalysts herein include the acidic mordenite catalysts Zeocat(trademark) FM-8/25H available from Zeochem; CBV 90 A available from Zeolyst International, and LZM-8 available from UOP Chemical Catalysts as well as fluoridated versions of the above commercial catalysts. Fluoridated mordenites can be prepared by a number of ways. A method of providing a particularly useful fluoridated mordenite is described in U.S. Pat. No. 5,777,187. The invention encompasses preferred embodiments in which the mordenites are fluoridated, but also has other preferred embodiments in which the mordenites are non-fluoridated.
Most generally, any alkylation catalyst may be used herein provided that the alkylation catalyst can (a) accommodate branched olefins as described elsewhere herein into the smallest pore diameter of said catalyst and (b) selectively alkylate benzene with said branched olefins and optionally mixtures thereof with nonbranched olefins. Acceptable selectivity is in accordance with a 2/3-Phenyl index of about 275 to about 10,000 as defined herein.
In other terms, the catalyst selections herein are made in part with the intention of minimizing internal alkylbenzene formation (e.g., 4-phenyl, 5-phenyl . . . ) The formulators contributing to the present invention have unexpectedly discovered that control of internal alkylbenzene sulfonate isomers in the present inventive surfactant mixtures in conjunction with introduction of limited methyl branching is very helpful for improving their perfonnance. The present invention connects this discovery to discoveries of the synthesis chemists in the present invention, who have determined how to control internal isomer content while providing limited methyl branching in the modified alkylbenzene sulfonate surfactant mixtures in accordance with the formulators"" prescriptions.
The extent to which internal isomer content needs to be controlled can vary depending on the consumer product application and on whether outright best performance or a balance of performance and cost is required. In absolute terms, the amount of internal isomer such as internal alkylbenzene isomer is preferably always kept below 25% by weight, but for best results, from 0 to 10%, preferably less than about 5% by weight. xe2x80x9cInternal alkylbenzenexe2x80x9d isomers as defined herein include alkylbenzenes having phenyl attachment to an aliphatic chain in the 4,5,6 or 7 position.
Without intending to be limited by theory, there are two reasons for which it is believed that the prefered alkylation catalysts are the above-described shape selective zeolitic type catalysts, especially mordenites. The first reason is to provide the selectivity of formation of preferred compounds such as branched and nonbranched 2-phenyl and 3-phenylalkylbenzenes. This selectivity is measured by the 2/3-phenyl index. The second reason is to control the amount of quaternary alkylbenzenes and thus quaternary alkylbenzenesulfonates.
Results with alkylation catalysts such as HF can give quite high levels of quaternary alkylbenzenes as shown in the literature (see J. Org. Chem. Vol 37, No. 25, 1972). This contrasts with the surprising discovery as part of the present invention that one can attain low levels of quaternary alkylbenzenes in catalyzed reactions of benzene with branched olefins, as characterized by 2-methyl-2-phenyl index. Even when the olefins used are substantially dibranched, as illustrated herein, a low 2-methyl-2-phenyl index of less than 0.1 can surprisingly be obtained.
Numerous variations of the present detergent compositions are useful. Such variations include:
the detergent composition which is substantially free from alkylbenzene sulfonate surfactants other than said modified alkylbenzene sulfonate surfactant mixture;
the detergent composition which comprises, at least about 0.1%, preferably no more than about 10%, more preferably no more than about 5%, more preferably still, no more than about 1% by weight of composition, of a commercial C10-C14 linear alkylbenzene sulfonate surfactant;
the detergent composition which comprises, at least about 0.1%, preferably no more than about 10%, more preferably no more than about 5%, more preferably still, no more than about 1% by weight of composition, of a commercial highly branched alkylbenzene sulfonate surfactant. (e.g., TPBS or tetrapropylbenzene sulfonate);
the detergent composition which comprises, a nonionic surfactant at a level of from about 0.5% to about 25% by weight of composition, and wherein said nonionic surfactant is a polyalkoxylated alcohol in capped or non-capped form having:xe2x80x94a hydrophobic group selected from linear C10-C16 alkyl, mid-chain C1-C3 branched C10-C16 alkyl, guerbet branched C10-C16 alkyl, and mixtures thereof andxe2x80x94a hydrophilic group selected from 1-15 ethoxylates, 1-15 propoxylates 1-15 butoxylates and mixtures thereof, in capped or uncapped form. (when uncapped, there is also present a terminal primary xe2x80x94OH moiety and when capped, there is also present a terminal moiety of the formxe2x80x94OR wherein R is a C1-C6 hydrocarbyl moiety, optionally comprising a primary or, preferably when present, a secondary alcohol.);
the detergent composition which comprises, an alkyl sulfate surfactant at a level of from about 0.5% to about 25% by weight of composition, wherein said alkyl sulfate surfactant has a hydrophobic group selected from linear C10-C18 alkyl, mid-chain C1-C3 branched C10-C18 alkyl, guerbet branched C10-C18 alkyl, and mixtures thereof and a cation selected from Na, K and mixtures thereof;
the detergent composition which comprises, an alkyl(polyalkoxy)sulfate surfactant at a level of from about 0.5% to about 25% by weight composition, wherein said alkyl(polyalkoxy)sulfate surfactant hasxe2x80x94a hydrophobic group selected from linear C10-C16 alkyl, mid-chain C1-C3 branched C10-C16 alkyl, guerbet branched C10-C16 alkyl, and mixtures thereof andxe2x80x94a (polyalkoxy)sulfate hydrophilic group selected from 1-15 polyethoxysulfate, 1-15 polypropoxysulfate, 1-15 polybutoxysulfate, 1-15 mixed poly(ethoxylpropoxy/butoxy)sulfates, and mixtures thereof, in capped or uncapped form; andxe2x80x94a cation selected from Na, K and mixtures thereof;
Further the present invention includes a detergent composition comprising (preferably consisting essentially of): (i) from about 0.01% to about 95%, by weight of composition, (preferably from about 0.5% to about 50%, more preferably from about 1%, preferably at least 2%, more preferably at least 4%, more preferably at least 6%, more preferably still at least 8% to about 35%) of modified alkylbenzene sulfonate surfactant mixture according to the invention; (ii) from about 0.00001% to about 99.9% by weight of composition (preferably from about 5% to about 98%, more preferably from about 50% to about 95%) of a conventional hand dishwasing adjunct; and (iii) from about 0.00001% to about 99.9% by weight of composition (preferably from about 0.1% to about 50%, more preferably from about 0.2% to about 40%, even more preferably form abour 0.5% to about 30%), of a surfactant selected from the group consisting of anionic surfactants other than said modified alkylbenzene sulfonate surfactant mixture, nonionic, cationic, amphoteric, zwitterionic and mixtures thereof; provided that when said detergent composition comprises any other alkylbenzene sulfonate than the alkylbenzene sulfonate of said modified alkylbenzene sulfonate surfactant mixture, said modified alkylbenzene sulfonate surfactant mixture and said other alkylbenzene sulfonate, as a mixture, have an overall 2/3-phenyl index of from about 275 to about 10,000 (preferably from about 350 to about 1200, more preferably from about 500 to about 700).
More generally, the hand dishwashing compositions can include the modified alkylbenzene sulfonate surfactant mixtures together with any conventional cleaning adjunct such as those wherein the adjunct is selected from the group consisting of builders, detersive enzymes, at least partially water-soluble or water dispersible polymers, abrasives, bactericides, tarnish inhibitors, dyes, solvents, hydrotropes, perfumes, thickeners, antioxidants, processing aids, suds boosters, suds suppressors, buffers, anti-fungal agents, mildew control agents, insect repellents, anti-corrosive aids, chelants and mixtures thereof.
Also more generally, the inventive detergent compositions can take the form of a liquid, powder, agglomerate, paste, tablet, bar, gel, liqui-gel, microemulsion, liquid crystal, or granule.
Related to the detergent composition embodiments are methods of their use, such as a method contacting soiled tableware in need of cleaning with either a neat or an aqueous solution of the composition of the invention. Such methods may optionally include the step of diluting the composition with water. Furthermore, the composition may be applied, either neat or as an aqueous solution directly to the tableware or surface to be cleaned or directly to a cleaning implement, such as a spounge or a wash cloth. Such methods are part of the present invention.
The present invention also encompasses hand dishwashing compositions comprising modified alkylbenzene sulfonate surfactant mixtures which are more particularly termed xe2x80x9c2/3-phenyl surfactant mixturesxe2x80x9d. Such mixtures are not the most preferred offered by the invention, but can be very economical.
Thus the invention includes a 2/3-phenyl surfactant mixture consisting essentially of: from 1% (preferably at least about 5%, more preferably at least about 10%) to about 60% (in one mode preferably less than about 50%, more preferably less than about 40%), by weight of surfactant system of a first alkylbenzene sulfonate surfactant, wherein said first alkylbenzene sulfonate surfactant is a modified alkylbenzene sulfonate surfactant mixture according to the first embodiment; and from 40% (in one mode preferably at least about 50%, more preferably at least about 60%) to about 99% (preferably less than about 95%, more preferably less than about 90%), by weight of surfactant system of a second alkylbenzene sulfonate surfactant, wherein said second alkylbenzene sulfonate surfactant is an alkylbenzene sulfonate surfactant mixture other than said modified alkylbenzene sulfonate surfactant mixture according to the first embodiment, and wherein said second alkylbenzene sulfonate surfactant has a 2/3-phenyl index of from about 75 to about 160 (typically said second alkylbenzene sulfonate surfactant is a commercial C10-C14 linear alkylbenzene sulfonate surfactant, e.g., DETAL(copyright) process LAS or HF process LAS though in general any commercial linear (LAS) or branched (ABS, TPBS) type can be used); provided that said medium 2/3-phenyl surfactant mixture has a 2/3-phenyl index of from about 160 to about 275 (preferably from about 170 to about 265, more preferably from about 180 to about 255). (of course it is equally possible within the spirit and scope of the invention to prepare any blend of the modified alkylbenzene sulfonate surfactant mixture of the invention with any known commercial linear or branched alkylbenzene sulfonate surfactant.
Processes for preparing a medium 2/3-phenyl surfactant mixture include those comprising a step selected from: (i) blending said first alkylbenzene sulfonate surfactant and said second alkylbenzene sulfonate surfactant; and (ii) blending the nonsulfonated precursor of said first alkylbenzene sulfonate surfactant and the nonsulfonated precursor of said second alkylbenzene sulfonate surfactant and sulfonating said blend.